Susu is solving the quadratic equation 4x2 – 8x – 13 = 0 by completing the square. her first four steps are shown in the table.

in which step did susu first make an error?

step 1
step 2
step 3
step 4

The given Quadratic equation is

These are the steps to determine the roots as well as solve the quadratic equation.

You can find the mistake by looking at the procedure of solving the quadratic equation by completing the square solved above.

if the eqn of the parabola is f(x) = (x-4)(x+2), we need to mult. this out to find the coordinates of the vertex.

then f(x) = x^2 + 2x - 4x - 8, and f(x) = x^2 - 2x - 8.

one way in which you can find the vertex is to calculate x = -b / (2a).   here, that comes to

        )

x = = 1.   f(1) = 1^2 - 2(1) - 8 = - 9.   vertex is at (1, -9).

        2(1) 

find another point on the curve:   let x=0, for which y=-8.   then (0, -8) is on the curve.   plot the vertex and this point and draw a smooth parabola thru both.

hope this

where are the graphs?

step-by-step explanation: